Refrigerator with automatic ice cube maker



June 17, 1969 w. FOX 3,449,919

REFRIGERATOR WITH AUTOMATIC ICE CUBE MAKER Filed March 8. 1968 la AY F' 20 Fig-2 29 7/ 33 34 4/ 38 R *2 37 I Z0 25 29a INVENTOR. 2/ /4 ////am 4 fax y ar- M WTTORNEYS 3,449,919 REFRIGERATOR WITH AUTOMATIC ICE CUBE MAKER William L. Fox, Niles, Ill., assignor to The Dole Valve Company, Morton Grove, Ill., a corporation of Illinois Filed Mar. 8, 1968, Ser. No. 711,590 Int. Cl. F250 1/04, 1/00 US. CI. 62-71 7 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This invention relates generally to the field of refrigerators of the household type and more particularly to refrigerators having a freezer compartment, a food storage compartment and an automatic ice cube maker in the freezer compartment.

In all of such refrigerators of which I am aware one or another means are provided for initiating a harvest-fillfreeze cycle after all of the water in the ice cube trays has frozen. In some known arrangements a thermostat is mounted in the tray to sense the water temperature and to initiate a harvest cycle after the water has turned to ice and the temperature has fallen below 32 F. Some such thermostats may take the form of thermistors.

Other control systems utilize a drop in back pressure in the suction line of the refrigeration compressor after all the water in the tray molds has frozen. Other systems utilize a thermal motor to initiate the harvest cycle, the thermal motor being subjected to the same temperature as is the ice cube tray.

While many of the known systems are adequate all have certain drawbacks. For example, where a thermostat or thermistor is placed in the ice cube tray, it is possible that the water in the mold to which the thermostat is exposed freezes before the water in all of the other molds is frozen. Where a reduction in back pressure is utilized, it is necessary to arrange the ice cube maker cooling coil in such proximity to the water in the tray so that the back pressure accurately reflects the condition of the water. Systems which include a thermal motor may be more expensive in manufacture.

SUMMARY OF THE INVENTION The present invention overcomes many of the drawbacks of the prior art by recognizing that the time period required for the water in the tray to freeze to ice depends upon air temperature within the freezer compartment and the contact of the air with the water in the tray.

For example, many of the refrigerators presently being manufactured include an air circulating fan for circulating air within the freezer compartment and, in some cases, additionally through the food compartment. Such air fans may be controlled to operate only when the refrigeration compressor-motor unit of the refrigerator operates. The operation of the compressor-motor unit is, in turn, controlled by a cold-control thermostat located in the food storage compartment.

The time required to freeze water in the ice cube tray when the temperature in the freezer compartment is below a certain level, say 25 F., and when the air cir- United" States Patent culating fan is operating, has been determined to be cumulative. In other words, both conditions need not be continuously met simultaneously, but the cumulated time in which both conditions do exist concurrently, even if they are occasionally interrupted, is consistent from harvest cycle to harvest cycle, absent a complete shutdown of the refrigerator.

The present invention utilizes this discovery by employing a control system which initiates the operation of the automatic ice cube maker through a harvest-fill-freeze cycle as a function of the cumulated running time of an electric timing motor which is energized only during such periods when the temperature in the freezer compartment is below a predetermined level and the air fan circulating air within the frezeer compartment is operating. At the expiration of such cumulated running time, the timing motor initiates operation of the automatic ice cube maker. The next timed cycle then begins.

Briefly, therefore, the present invention comprises a method of and apparatus for controlling the initiation of a harvest-fill-freeze cycle of an automatic ice cube maker in a refrigerator having a freezer compartment in which the ice cube maker is situated, a food storage compartment and an air circulating fan for circulating air within the freezer compartment which comprises the steps of and means for sensing the temperature within the freezer compartment, operating the air circulating fan when the temperature in the food storage compartment is above a first predetermined level and initiating a hatvest-fill-freeze cycle of the automatic ice cube maker only after the temperature in the freezer compartment has been below a second predetermined level for a predetermined cumulative time period during which the air circulating fan has been operating.

The expiration of the predetermined cumulative time period may be indicated by an electrically operated timing motor which makes, for example, one complete revolution during such period and which is energized only when the temperature in the freezer compartment is below a given level and when the air circulating fan is operating. Suitable cam and cam-operated switch means are operatively connected to the timing motor and to a drive means of the automatic ice cube maker for initiating the operation thereof after the timing motor has completed one revolution. On the other hand, the timing motor may, itself, comprise the ice maker drive means.

It is, therefore, an object of the present invention to provide a method of and apparatus for controlling the operation of an automatic ice cube maker through successive harvest-fill-freeze cycles as a function of time during which the air surrounding the ice maker is circulating and is below a predetermined temperature level.

Another object of the invention is to provide a simple and inexpensive mechanism for controlling the operation of a automatic ice cube maker.

Another object is to initiate a harvest-fill-freeze cycle as a function of the cumulated running time of an electric timing motor which is energized only when air below a predetermined temperature level is being circulated around the ice maker.

Many other features, advantages and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheets of drawings, in which preferred structural embodiments incorporating the principles of the present invention are shown by way of illustrative example only.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a front elevational view of a refrigerator having a food storage compartment, a freezer compartment and an automatic ice cube maker located within the freezer compartment, constructed in accordance with the principles of the present invention.

FIGURE 2 is a schematic illustrating an exemplary embodiment of the electric circuitry of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGURE 1, a double compartmented refrigerator of the household type constructed in accordance with the principles of the present invention is indicated generally at reference numeral and is more particularly characterized as comprising a cabinet 11 having a partition wall 12 dividing the cabinet into a freezer compartment 13 and a food storage compartment 14. The two compartments have individual closure doors 16 and 17 respectively hinged to one side of the cabinet. Mounted within the freezer compartment 13 is an automatic ice cube maker 18. A collection basket 19 is located directly below the automatic ice cube maker 18 to collect the ice cubes as they are harvested and dropped from the ice cube maker 18.

Also provided within the refrigerator 10 is means for circulating air within the freezer compartment 13. In the illustrated embodiment, the air circulation means comprises a propeller-type fan 20 mounted on the inside of the freezer compartment 13 and adapted and arranged to circulate the air across the ice cube molds of the ice cube maker 18.

A refrigeration compressor-motor unit 21 is mounted within a base portion 22 of the cabinet 11 for providing the necessary refrigeration effect to cool both the freezer compartment 13 and the food storage compartment 14. Suitable refrigeration coils and associated controls are also provided to maintain the temperature of the freezer compartment 13 substantially below that of the food storage compartment 14. The food storage compartment 14, for example, may desirably be maintained at a temperature of about -40 F., whereas the temperature of the freezer compartment 13 may desirably be in the order of about 1520 F.

An on-otf control for the compressor-motor unit 21 comprises a temperature responsive switch such as a coldcontrol thermostat indicated at reference numeral 23. The thermostat is situated and arranged so as to sense the temperature of the air within the food storage compartment 14 and in the illustrated embodiment is conveniently mounted on the side wall of the food storage compart ment. The thermostat 23 is adapted to energize the compressor-motor unit 21 when the temperature within the food storage compartment 14 rises above a predetermined level, and to deenergize or disconnect the compressormotor unit when the temperature within the food storage compartment falls below a minimum predetermined temperature.

Although the compressor-motor unit 21 cycles on and off as a function of the temperature within the food storage compartment 14, the refrigeration system is constructed and arranged so that the freezer compartment 13 will be maintained within predetermined maximum and minimum temperature levels so long as the freezer compartment 14 is maintained within the desired maximum and minimum temperature levels of that compartment.

The automatic ice cube maker 18 may be of any type of which I am aware. Some such devices utilize a continuously moving conveyor belt having the ice cube molds formed therein. Other devices utilize ice cube trays of the twist-turn type for ejection of the ice cubes. Other devices employ movable pistons or plungers for ejecting cubes out of the cube molds or cavities.

In the illustrated embodiment, the automatic ice cube maker 18 includes an electric motor drive indicated at reference numeral 24 in the schematic shown in FIG- URE 2. Electric motor drives may be employed in most or perhaps all of the automatic ice cube makers currently being manufactured but it will be understood that the present invention is applicable to automatic ice makers utilizing thermal motors or other power or drive devices wherein the ice cube maker operates through successive automatically controlled harvest-fill-freeze cycles.

As shown in FIGURE 2, the driving motor 24 is connected into electric circuitry indicated generally at reference numeral 26 and which includes a pair of conductors 27 and 28 adapted for connection to a source of suitable electric power through terminals 27a and 28a.

Also included within the circuit 26 is an electric timing motor 29 which serves to control the operation of the ice cube maker 18 through successive harvest-fill-freeze cycles by controlling the energization of the driving motor 24.

As shown, a control cam 30 is driven by the timing motor 29 through an interconnecting linkage such as a drive shaft indicated at reference numeral 31. The periphery of the cam 30 has a detent 32 formed therein for receiving a cam follower 33 formed on an actuating arm 34 of an electric control switch 36. Switch 36 is normally biased to a closed position and when the cam follower 33 registers with the detent 32 the contacts of the switch 36 are closed. When the cam follower 33 rides out of the detent 32, the contacts of switch 36 are opened.

In the embodiment illustrated, the cam follower 33 registers with detent 32 to close switch 36 and thus to energize the driving motor 24 once for each revolution of the electric timing motor 29. Thus, each time that the timing motor 29 turns one complete revolution, the driving motor 24 is energized to initiate a harvest-fill-freeze cycle of the automatic ice cube maker 18.

The timing motor 29, in turn, is connected in series with a temperature responsive switch 37 which is located so as to sense the temperature of air within the freezer compartment and which may be conveniently referred to as the ice maker thermostat. As indicated in FIGURE 1, the freezer thermostat 37 may be located on the same cabinet wall on which the air circulating fan 20 is mounted.

In the illustrated embodiment, one set of contacts 38 of the cold-control thermostat 23 is also wired in series with the timing motor 29 and the ice maker thermostat 37. Another set of contacts indicated generally at 39 serve to simultaneously energize the air circulating fan 20 and the refrigeration compressor-motor unit 21. When the temperature of the air within the food storage compartment 14 rises above a predetermined level, contacts 38 and 39 of the cold-control thermostat 23 are both closed. This has the effect, of course, of energizing the air fan 20 and the compressor-motor unit 21, and also has the effect of energizing the timing motor 29 but only if the ice make thermostat 37 is also closed. Thermostat 37 is only closed, however, when the temperature of the air within the freezer compartment 13 is below a predetermined level.

As a consequence, the timing motor 29 is energized only during such periods of time in which the air circulating fan 20 is energized and the temperature within the freezer compartment 13 is below a predetermined level.

In the illustrated embodiment the driving motor 24 makes one complete revolution during each harvest-fillfreeze cycle. In order to maintain energization of the driving motor 24 after it has been initially energized by switch 36, another switch 40 which is of the normally open type and which may be conveniently referred to as a running switch is wired to the driving motor 24 in parallel with switch 36. Suitable shaft driven cam means 41 are connected to the driving motor 24 to maintain the running switch 40 in a closed position for one complete revolution of the driving motor 24 after being initially energized by switch 36 as will be understood by those skilled in the art.

Although the illustrated embodiment of the invention includes both a timing motor and a drive motor it is apparent that the timing motor can also be used to drive the automatic ice cube maker thus obviating use of a separate driving motor. For example, suitable mechanical linkages can be interconnected between the timing motor and the ice cube maker to operate the ice cube maker during a portion of each revolution of the timing motor. In addition a thermal motor may be used as a driving motor. In such an arrangement a heater may be associated with the thermal motor and energized by a switch responsive to rotation of the timing motor.

Although minor modifications might be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably come within the scope of my contribution to the art.

I claim as my invention:

1. In a refrigerator having a freezer compartment, an automatic ice cube maker in the freezer compartment operable through successive harvest-fill-freeze cycles, an electric motor driven fan for circulating air in the freezer compartment and an electric thermostat controlling the operation of the air circulating fan, the improvement of means for controlling the operation of the automatic ice cube maker comprising:

electric timing means operatively connected to the automatic ice cube maker for initiating operation thereof only after the timing means has been energized for a predetermined cumulative time period, and

electric circuit means including temperature responsive means for energizing said timing means only when the temperature in the freezer compartment is below a predetermined level and the air circulating fan is operating.

2. The refrigerator as defined in claim 1 wherein said timing means comprises an electric timing motor and wherein said timing means and energizing means further comprises an electric thermostat for sensing the temperature of the air in the freezer compartment.

3. The refrigerator as defined in claim 1 and including,

electric drive means for driving the automatic ice cube maker through successive harvest-fill-freeze cycles, switch means actuable to energize said ice cube maker drum means, and

cam means operatively connected to said timing motor for actuating said switch means after said predetermined cumulative running time of said timing motor has expired.

4. The method of controlling the initiation of successive harvest-fill-freeze cycles of an automatic ice cube maker in a refrigerator having a freezer compartment in which the ice cube maker is situated and an air circulating fan for circulating air within the freezer compartment comprising the steps of,

intermittently operating the air circulating fan, sensing the temperature in the freezer compartment, and initiating a harvet-fill-freeze cycle of the automatic ice cube maker only after the temperature in the freezer compartment has been below a predetermined level for a predetermined cumulative time period during which the air circulating fan has been operating.

5. A household refrigerator comprising,

a cabinet having a freezer compartment and a food storage compartment,

an automatic ice cube maker in said freezer compartment operable through successive harvest-fill-freeze cycles,

a refrigeration compressor-motor unit for cooling said compartments,

an air circulating fan in said cabinet for circulating air in said freezer compartment, and

means for initiating the operation of said automatic ice cube maker comprising means for sensing the temperature within said food storage compartment, means for operating said refrigeration compressormotor and said air circulating fan together and only during periods in which the temperature in the food storage compartment. is above a first predetermined level, means for sensing the temperature within said freezer compartment, and means for initiating a harvest-fill-freeze cycle of the automatic ice cuber marker only after the temperature in the freezer compartment has been below a second predetermined level for a predetermined cumulative time period during which the compressor-motor unit and the air circulating fan have been operating. 6. The refrigerator as defined in claim 5 wherein said initiating means comprises,

electric circuit means including a constant speed electrically operated timing motor operatively connected to said automatic ice cube maker for initiating operation of said ice cube maker after a predetermined cumulative running time of said timing motor, and

wherein said temperature sensing means for said food storage compartment and for said freezer compartment both comprise temperature-responsive electric switch means wired in said circuit means with respect to said timing motor so as to energize said timing motor only when both of said electric switch means are closed.

7. The refrigerator as defined in claim 6 wherein said automatic ice cube maker comprises an electric driving motor, and including cam and cam operated switch means operatively interconnecting said timing motor and said driving motor for energizing said driving motor after said predetermined cumulative running time of said timing motor has expired.

References Cited UNITED STATES PATENTS 3,055,186 9/1962 Linstromberg et al. 62344X WILLIAM E. WAYNER, Primary Examiner.

US. Cl. X.R. 62-233 

